Spiritual Weapon and Twilight Knife

[Derek Dalton]

So read through both spells and the forums and I haven't seen anything regarding my question. So I'm playing a Thuerge with both spells. So if I'm correct I cast Spiritual Weapon the next round cast Twilight Knife. Third round I can simply hide and both spells attack on my turn without any action on my part except to move them.

[avr]

Spiritual weapon is not you. Twilight knife attacks the same target as you each round. If the spiritual weapon attacks but you don't, twilight knife does nothing.